/*******************************************************************************
 *  Copyright (c) 2005, 2016 IBM Corporation and others.
 *  All rights reserved. This program and the accompanying materials
 *  are made available under the terms of the Eclipse Public License v1.0
 *  which accompanies this distribution, and is available at
 *  http://www.eclipse.org/legal/epl-v10.html
 * 
 *  Contributors:
 *     IBM Corporation - initial API and implementation
 *     Bjorn Freeman-Benson - initial API and implementation
 *     Wind River Systems - adopted to use with DSF
 *******************************************************************************/
package org.eclipse.cdt.examples.dsf.pda;

import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.RejectedExecutionException;

import org.eclipse.cdt.dsf.concurrent.DataRequestMonitor;
import org.eclipse.cdt.dsf.concurrent.Query;
import org.eclipse.cdt.dsf.concurrent.RequestMonitor;
import org.eclipse.cdt.examples.dsf.pda.launch.PDALaunch;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.Plugin;
import org.eclipse.core.runtime.Status;
import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.core.ILaunch;
import org.osgi.framework.BundleContext;

/**
 * The main plugin class to be used in the desktop.
 */
public class PDAPlugin extends Plugin {
    
    public static String PLUGIN_ID = "org.eclipse.cdt.examples.dsf.pda"; 
    
    // Debugging flag
    public static boolean DEBUG = false;

	//The shared instance.
	private static PDAPlugin plugin;
	
	//Resource bundle.
	private ResourceBundle resourceBundle;

	// Bundle context used in registering and retrieving DSF (OSGi) services.
	private static BundleContext fContext;
	
	/**
	 * Unique identifier for the PDA debug model (value 
	 * <code>pda.debugModel</code>).
	 */
	public static final String ID_PDA_DEBUG_MODEL = "org.eclipse.cdt.examples.dsf.pda.debugModel";
	
	/**
	 * Name of the string substitution variable that resolves to the
	 * location of a local Perl executable (value <code>perlExecutable</code>).
	 */
	public static final String VARIALBE_PERL_EXECUTABLE = "dsfPerlExecutable";

	/**
	 * Launch configuration attribute key. Value is a path to a perl
	 * program. The path is a string representing a full path
	 * to a perl program in the workspace. 
	 */
	public static final String ATTR_PDA_PROGRAM = ID_PDA_DEBUG_MODEL + ".ATTR_PDA_PROGRAM";
	
	/**
	 * Identifier for the PDA launch configuration type
	 * (value <code>pda.launchType</code>)
	 */
	public static final String ID_PDA_LAUNCH_CONFIGURATION_TYPE = "org.eclipse.cdt.examples.dsf.pda.launchType";	
	
	/**
	 * The constructor.
	 */
	public PDAPlugin() {
		super();
		plugin = this;
	}

	/**
	 * This method is called upon plug-in activation
	 */
	@Override
    public void start(BundleContext context) throws Exception {
        fContext = context;
        DEBUG = Boolean.parseBoolean(Platform.getDebugOption(PLUGIN_ID + "/debug"));  //$NON-NLS-1$
		super.start(context);
	}

	/**
	 * This method is called when the plug-in is stopped
	 */
    @Override
	public void stop(BundleContext context) throws Exception {
        shutdownActiveLaunches();
		super.stop(context);
		plugin = null;
		resourceBundle = null;
		fContext = context;
	}

	/**
	 * Returns the shared instance.
	 */
	public static PDAPlugin getDefault() {
		return plugin;
	}

	/**
	 * Returns the string from the plugin's resource bundle,
	 * or 'key' if not found.
	 */
	public static String getResourceString(String key) {
		ResourceBundle bundle = PDAPlugin.getDefault().getResourceBundle();
		try {
			return (bundle != null) ? bundle.getString(key) : key;
		} catch (MissingResourceException e) {
			return key;
		}
	}

	/**
	 * Returns the plugin's resource bundle,
	 */
	public ResourceBundle getResourceBundle() {
		try {
			if (resourceBundle == null)
				resourceBundle = ResourceBundle.getBundle("org.eclipse.debug.examples.core.pda.DebugCorePluginResources");
		} catch (MissingResourceException x) {
			resourceBundle = null;
		}
		return resourceBundle;
	}
	
	public static BundleContext getBundleContext() {
	    return fContext;
	}
	
	/**
	 * Return a <code>java.io.File</code> object that corresponds to the specified
	 * <code>IPath</code> in the plugin directory, or <code>null</code> if none.
	 */
	public static File getFileInPlugin(IPath path) {
		try {
			URL installURL =
				new URL(getDefault().getDescriptor().getInstallURL(), path.toString());
			URL localURL = Platform.asLocalURL(installURL);
			return new File(localURL.getFile());
		} catch (IOException ioe) {
			return null;
		}
	}	
	
	/** 
	 * Shuts down any active launches.  We must shutdown any active sessions 
	 * and services associated with this plugin before this plugin is stopped.
	 * Any attempts to use the plugins {@link BundleContext} after the plugin
	 * is shut down will result in exceptions. 
	 */
	private void shutdownActiveLaunches() {
	    for (ILaunch launch : DebugPlugin.getDefault().getLaunchManager().getLaunches()) {
	        if (launch instanceof PDALaunch && !((PDALaunch)launch).isShutDown()) {
	            final PDALaunch pdaLaunch = (PDALaunch)launch;
	            
	            Query<Object> launchShutdownQuery = new Query<Object>() {
	                @Override
	                protected void execute(DataRequestMonitor<Object> rm) {
	                    pdaLaunch.shutdownServices(rm);
	                }
	            };
	            
	            try {
	                pdaLaunch.getSession().getExecutor().execute(launchShutdownQuery);
	            } catch (RejectedExecutionException e) {
	                // We can get this exception if the session is shutdown concurrently
	                // to this method running.
	                break;
	            }

	            // The Query.get() method is a synchronous call which blocks until the 
	            // query completes.  
	            try {
                    launchShutdownQuery.get();
                } catch (InterruptedException e) { 
                    getLog().log(new Status(IStatus.ERROR, PLUGIN_ID, "InterruptedException while shutting down PDA debugger launch " + pdaLaunch, e.getCause()));
                } catch (ExecutionException e) {
                    getLog().log(new Status(IStatus.ERROR, PLUGIN_ID, "Exception while shutting down PDA debugger launch " + pdaLaunch, e.getCause()));
                }
	        }
	    }
	}
	
    
    public static void failRequest(RequestMonitor rm, int code, String message) {
        rm.setStatus(new Status(IStatus.ERROR, PLUGIN_ID, code, message, null));
        rm.done();
    }
    
    public static void debug(String debugString) {
        if (DEBUG) {
            System.out.println(debugString);
        }
    }
}
